Vacuum power hammer



May 1o; 1932.

J. c. CAMPBELL VACUUM POWER HAMMER 3 Sheets-Sheet Filed Feb. l5, 1928May lo, 1932.

J. c. CAMPBELL VACUUM POWER HAMMER Filed Feb. 15, 1928 3 Sheets-Sheet 2rhs@ A 'My 10, 1932- J. c. CAMPBELL 1,857,138

VACUUM POWER HAMMER Filed Feb. l5, 1928 3 Sheets-Sheet 3 vwantozPatented May 10, 1932 UNITED f sraras. oFFlcE A Jamas c'.- oAMPBnLI.,orNEW Yoann. Y.,.AssIGNon tro PORTABLE In HAMMER Colr- 1 ram?, INC., aconronarron ornnw YoRx *n 'y vvacunar POWER HAMMER lApplication'1111511February 15, 192s. serial No. 254,364#

This inventionl relates to an improvement in a `vacuum powerhammer andthe novelty consists in the adaptationlandfarrangement of parts as willbe more fullyv hereinafter pointed out.

Y Vacuum power hammers require real 'prec1s1on both 1n the manufactureofthe parts Vand in the assembling ofthe same. Many of the patents inlthis art cover. devices which are either difficult to manufacture withprecision orare impossible of precise assembly or both. c .c My deviceovercomes both of these weaknesses whichare fatal to volume productionand does so in a practical and eiicient manner thereby furnishing adevice which is practical and insures exact precision both in man--ufacture and assembling.

My device is' also*y adapted to easy and ready 'separation of the innerand outer cyl- -inders so as to permit of proper cleaning andVlubrication of the .otherwise inaccessible interior parts whereby moreefficient and .continuous operation is secured yand the danger vofinjury'to the interior through failure to clean is eliminated. .f 2:

Referring tothe drawings Figure 1 is a top plan view of my device withthe central portion shown-.in section,` and with part o the drivingmechanism removed.

Figure 21S-a vertical section through the driving mechanismand housing.j Figure 3 is :a longitudinal section `of the cylinders as shown inFigure 1.

Figure 4 is an end view 4of the cylinders looking in at the left handend of Figure 3.

Figure 5 is a side vieW of the inner cylinder.

Figure 6 is an end view of'Figure5 looln'ng in at theleft hand end. l'

Figure 7 is an end view of Figure 5 looking in atthe right hand end.

Figure 8 isa side viewofa and eccentric. p n vFigure 9 is aiverticalsection of thesame through the center. l l. f

Figure '10 is a top plan view of a second form of my device with theshown Vin section;

driving plate central portion Figure 11 is aV sidejview of the innercyl- Y inderas shownk in Figure 10. c

- Figure 12 isl an end view of Figure 11 look'- ing in from thel lefthand end.

Figure 13 is an end View of Figure 11 look.-

ingin from the right hand end. i

In the drawings 14 is an innercylinder adapted to fit an 'outer cylinder15 in a drive fit and has longitudinal cut outs 16 andr circular cutouts 17 which connectsaid longif' tudinal cut outs 16 and said circularcut outs 17 have holes 18 running through to th inside' vof saidcylinder 14. .f The lower end' ofthe outer cylinder 15 terminates in atool holder 19 which has. acylindrical boring 20 'terminatingatitsvouter end in an internal threaded portion 21,V in which is mounted aspring 22 and a flange ring 23, both the spring 22 andthe flange ringbeing held under compressed tension by nects the boring 20`and theinside of innerv cylinder 15 has atits upper end "'10 means ofv athreaded adjustment plug 24 boring'28. Adrivingmechanism housing 29 isinternally threaded at 30 so as to engage 'the external .threading 26of-the cylinder 15K.k

The upper end of said housing terminates in a Y handle31Y of usualconstruction. The housing-29 has a ball bearing 32 which is adapted toreceive a spindle 33 of 'a driving plate 34 which plate also has aneccentric projection 35 inwhich there is a circular cut out or bear-'ing 36. The exteriory ofthe eccentric 35 is 'also adapted tofbe used asa bearing over which aplunger connector arm37ihaving a circular head38'y is adapted'to be mounted. An eccentric pin 39 of a driven plate 40is adapted to itinto the bearing 36 of thel eccentric projectiony 35thereby holding the .,plunger connectorv 36 in position on the eccentricprojection 35 so that the circular head Y itis adapted to receive theinternally threaded cap 47. The circular sub-housing is f adapted tocontain suitable grease for lubrieating the device, indicatedat 48.rl"he lower end of the plunger arm u37 terminates in a ball 49: Awhichis adapted to lit a socket 50 'o f a plunger 51, which plunger is'adapted'to slide on theinsideof the inner cylinder 14. Lower portions ofthe driving plate 34 and driven plate ,'40 aredesignated as 58 and 59,respectively, and are both thickened substantially and therefore adaptedto act as counter-balances to the connector arm 37 and plunger 51.Theplunger 51 has a'n air pocket 52 which is adapted to receive the head53 of a tappet or hammer 54, which head 53Yis `of smaller diameterthanthe hammer 54v and forms therewith a shoulder 55V adapted to registerjust below the upper circular cutout 17 in the inner cylinder 14 whenthe hammer y54 is inthe lower positiorn The spindle 33V terminates in anexternal threading55, over which a flexible shaft, not shown, leadingfrom a source of power, Awhich also is not shown herein, is adapted tobeY fastened and retainedinposition by means ofV a coupling56 in which aremounted flattened keys adapted to lock a flattened-portion of theengaging ilexible shaft.

In the threading 28 is mounted a screw 57 which engages-the baseofhousing 29 and eects. a locking when the housing 29 vis screwed downonto the cylinder-15 at 27.

Y Several registering cut-outs 17 maybe arranged so asto varythe amountof vacuum formed inthe inside of the inner cylinder v14,

y lwhich variationwill varythe blow Of the vhammer 54 indirect ratiowiththe variation ofthe vacuum., Y

It will lbe quite apparent with the two cylinders 14 and 15 that thelongitudinal cutyoutsV 16 andthe circular cut-outs 17 can be cut on theouter surface of the inner cylinder v14 or fon the innerV surface oftheouter cylinder 15 so that the operation of my device will be equallyVefficient.'

Th'eoperation of my device islas follows:

The-power is turned on from the :source of powerwhich is notl shown,which thereby rotates the spindle 33,- the driving plate 34 and "throughthe eccentrics 35 and 39 rotates the b driven pla'te'44 therewith,vwhich carry the "connecting arm 37 ltherewith, thereby raisingandlowering the vpli`in`ger 1 which isv connected to 'said'arn'i 37through the-bfall49 and socket 50. The tappet 54 is in its normal orlower position as shown in Figure 1, and the air is therefore maintainedat atmospheric pressure on the inside of the cylinder 14 as itcirculates freely from both ends of the device, through the toolholderlQand the power housing end of the device, :audcirculating Y freelythroughthe longitudinal cut-outs 16 and thencethrough, the. circular.eut-Outil? to the insideV of theinnercylinder-l'4: -As'the opera-torthenl holds the handle 31 with one hand and directs the application ofthe tool 25 with the 'other hand and presses down to perform theproposedoperation with the tool 25, the upper or handle end of the tool willproject through the circular boring 60` so that the tool 25 pushes withit .on the tappet or hammer 54, thereby raising the head 53 4until itstops vregistering with ,the circulan eut out 17 whereupon kthe slidingofthe plunger 51 in the upward-orbaekward movementwill cause a vacuumonI the inside of the inner cylinder 14 sothe hammer54 will slide upthereinuntil the head 53 cushions in theair pocket 52 of the vplunger51,whereupon -itwill be pushed downwardly by the downward drive of theplunger 51 and the lower end or base of Y the hammer 54 will'strikezablowon the upper or handle end ofthe tool 25., This operation willcontinue with .the; .rapid iblows 'of the Ahammer 54,011 the tool 25until the operator releases the pressure on the tooly 25, `Whereupon thespring 22;will,'throu'gh'the;pushing of the flange ring 23 againstthesholder of the tool 25, restore the-tool to its normal position. so,that .the upper end Vdoes not .pro- )ect agalnst the lower end of thehammer V54, and the hammer 54 will slide Adown to itsl normal positionwhere the head v53 registers with the cutout 17, whereby.atr'nos'pherie`pressure 1s again restored to the cylinder14 thereby 'stoppingthemovement up anddown of the khammer-54m the cylinder14. In they deviceshownfin Figures 1'0 to.13 the inner cylinder 14l may be .drivenintoposition :1n the outer; cylinderV 115 .through thek lower end of theouter cylinder 15,th'at is through the tool holder '19 Vand theoutercylinder 15 has an inner circular shoulder 61 ;against which theupper end of the yinner cylinder` 14 is adapted toresty and therebylimit its upward`movement d, 1 i

The construction of the adjustment 24 VY and thelock nut 26 ashown inFigure 1 may be applied to the construction showniii Fig'- ure10. 7

Iclaim: v In a vacuumpower hammer the,eombii'iation of a two piececylinder comprising a tool odying means for contro lling thehammer blowby limiting the inward movement l"of said tool, Yareciprocatorypluger'in/Said cylifndef having anV air cushin pcket',means fr actuating said plunger, and'areciprocatoiy holder :at one -endcarryin a tool andgemhammer having a head adapted to cushion in said aircushion pocket movable in said cylinder between said tool holder andsaid plunger, and said cylinder embodying means for i producing a vacuumbetween the end of the hammer and the end of the plunger when saidplunger is moving in a direction away from said tool holder and forcingsaid hammer against the end of said tool holder when the o plunger movesin the opposite direction consisting of longitudinal grooves cut on theouter surface of the inner cylinder member and also having circular cutouts having through borings which borings are in alignment with saidgrooves adapted to maintain atmospheric pressure therein, means forinterrupting the same between the hammer and plunger and means wherebysaid cylinder members may be assembled at the tool holder end of theouter member.

In testimony whereof I aiiiX my signature.

JAMES C. CAMPBELL.

